skip to main content | skip to footer
N.C. Department of Environment and Natural Resources

NC Department of Environment and Natural Resources
Environmental Assistance and Customer Service - deao - recycling - mercury containing thermostats

Environmental Assistance and Customer Service

Mercury-Containing Thermostats

A home's thermostat containing Mercury in the electrical control mechanism.Mercury is an excellent conductor of electrical current. This toxic element was used extensively in the electrical control mechanism of thermostats. Approximately three ounces of elemental mercury sealed in a glass ampoule with metal electrical conductors serves as the active control device in thermostat mechanisms. The ampoule is attached to a wound bi-metallic strip that contracts and elongates in proportion to temperature variations. The mercury-containing thermostat serves as a primary control for contactors that in turn provide power to HVAC and/or industrial process equipment. Improvements in electronic control system technology have rendered mercury-containing thermostats inadequate for state-of-the-art mechanical equipment control. Many of these antiquated mercury thermostats are still in use and are being replaced as systems become too costly to operate and maintain.

Mercury contained in old thermostats is likely to be released into the environment if the glass ampoule is mishandled. Disposal of mercury-containing devices in municipal solid waste collection is forbidden by state and federal law. Mercury-containing thermostats are regulated as universal waste and are the responsibility of the generator at the time the device is considered a waste material.

Mercury Thermostat Recycling

Full Title: Thermostat Recycling Corporation
Full Work Author: National Electrical Manufacturers Association
Abstract: This website explains how the not-for-profit organization facilitates the collection and recycling of mercury-containing thermostats.

Full Title: Earth 911
Full Work Author:Earth 911.com
Abstract: This website specializes in providing consumers with accessible and actionable recycling information across the country. The recycling directory contains information for recycling more than 240 different products. 

Regulations Affecting Thermostats

Full Title: Universal Waste Rule 
Full Work Author: U.S. EPA Office of Solid Waste
Abstract: As part of the U.S. Environmental Protection Agency’s commitment to reinvent environmental regulations, the agency recently issued the “Universal Waste Rule.” This rule is designed to reduce the amount of hazardous waste items in the municipal solid waste stream, encourage recycling and proper disposal of certain common hazardous wastes, and reduce the regulatory burden on businesses that generate these wastes.

Full Title: Removal and Recycling of Mercury-Containing Products from Structures to be Demolished
Full Work Author: General Assembly of North Carolina
Abstract: Session Law 2010-180, House Bill 1766 requires the removal of mercury-containing thermostats prior to structural demolition and further bans disposal of mercury-containing products in unlined landfills.

Web Content Display Web Content Display
38322 FEEDBACK

Your input is valuable to us. Please send us your feedback.

What type of feedback would you like to send?*

Ask a Question Report a Problem Have a Concern Make a Comment

(If you would like us to respond please include your phone or e-mail.)

Your Question has been sent. Thank you!

An internal server error prevented Your Question from being sent.
Please try again later, or call Toll-Free (877) 623-6748 for immediate assistance.

Please complete all highlighted items

Your Problem has been sent. Thank you!

An internal server error prevented Your Question from being sent.
Please try again later, or call Toll-Free (877) 623-6748 for immediate assistance.

Please complete all highlighted items

Your Concern has been sent. Thank you!

An internal server error prevented Your Question from being sent.
Please try again later, or call Toll-Free (877) 623-6748 for immediate assistance.

Please complete all highlighted items

Your Comment has been sent. Thank you!

An internal server error prevented Your Question from being sent.
Please try again later, or call Toll-Free (877) 623-6748 for immediate assistance.

Please complete all highlighted items

*If you are a DENR employee with an I.T. issue, please submit a DOTS ticket.